That's unfortunate, it sounds like the game works at first, but then it becomes unresponsive. Does this happen at the same point every time (i.e. day 3 or after purchasing a specific upgrade)?
Are you playing in the browser? If so, which one? Do you experience the same issue with the downloaded version? That would help us determine if this is a general problem with the game, or something that only happens on a specific platform/your specific setup. Thanks!